tains myricyl alcohol, behaves like beeswax, and the same holds with Chinese
insect wax, which contains ceryl alcohol.
(a) BY MEANS OF THE ACETYL NUMBER. The substance 1 is saponified
and the unsaponifiable part extracted by the usual methods or preferably
by Leys' method (see 8) and its acetyl number determined (see General
Methods, u). If this number is found to be zero, the presence of the wax
may be excluded; if, however, there is an acetyl number, the presence of
the wax may be assumed and the amount may be calculated approximately
from the fact that the mean acetyl number of the higher alcohols of the
wax is 122 and that the wax contains, on the average, about 40% of higher
(b) BY TRANSFORMATION OF THE MYRICYL ALCOHOL INTO MELISSIC
ACID. 3 grams of unsaponifiable substance, extracted as for the pre-
ceding test, are intimately mixed with about 10 grams of powdered soda
lime and a little caustic soda, the mixture being placed in a large test-tube
and this plunged into a sand-bath and heated to 200-220° for 2 hours ;
the temperature is measured with a thermometer immersed in the substance
and used at intervals as a stirrer. When cold, the substance is extracted
with petroleum ether, the solvent evaporated and the residue weighed.
If the weight is equal or nearly equal to that of the substance used, the
presence of wax is excluded, but if the petroleum ether extract is appreciably
less in weight than the substance taken, wax may be present. In the
latter case the difference between 5 grams (weight of substance used) and
the weight of the residue represents the myricyl alcohol contained in the
5 grams of unsaponifiable matters. If, then, the percentage of unsaponi-
fiable matter in the substance is known, the myricyl alcohol contained in
100 parts of the substance itself and hence approximately the percentage
of the wax present may be calculated, since 38 parts of myricyl alcohol
correspond on the average with 100 parts of beeswax.
The purity of a wax is judged first of all from the results of the determina-
tions of the various characters, account being naturally taken of the origin
and nature of the wax : if all or some of these characters lie outside the limits
indicated in Table XLIX, the wax is not genuine.
A low specific gravity indicates the presence of solid paraffin or ceresine,
stearic acid or tallow, and a high one that of carnauba wax, Japan wax or colo-
The acid, saponification, ester, ratio, iodine and refractometric numbers
are also influenced more or less by the presence of various foreign substances,
as is shown in the following table (page 439), where the mean characters of
ordinary virgin wax are-compared with those of the substances most usually
employed to adulterate it.
It should, however, be noted that mixtures may be prepared, with, or without
beeswax, so as to have the characters given above for the pure wax. Con-
sequently, if it is certain that a wax is adulterated if its characters are abnormal,
normal characters do not necessarily correspond with a pure wax ; in the latter
case, tests 6-n must be carried out.
1 In the case of plasters or waxed paper or cloth, the sample is extracted with
boiling benzene, the liquid filtered and evaporated and the residue examined.22—24